Blender - apply image texture to specific parts of the object
A solution is that first you make two material slots. Give one slot any other texture you want and the other slot the image texture you want to apply to a specific part of mesh. Then go to edit mode, select the parts of your mesh you wan't your material to appear on and then press apply after selcting the right material.
Here are some tutuorials from youtube for beginners: https://www.youtube.com/watch?v=ms89wP8m4ZU
https://www.youtube.com/watch?v=CXpbK2T1HJA